A biological medicine is a medicine that contains one or more active substances that are made by or extracted from living cells or organisms.
What is a Biosimilar?
Biological medicine’s are usually made up of proteins that are naturally made in the body and are developed for the treatment of many cancers including lymphoma.
Once a biological medicine is produced the medicine is placed under patent. A patent is a license that gives the original developer of the medicine the legal right to be only one on the market for several years. Once this patent expires other companies can produce medicines that are like the original biological medicine and these are called biosimilar medicines.
Biosimilar medicines are like the original medicine and can be used to treat the same diseases in the same way as the biological medicines. These biosimilar medicines have been tested and have shown to be safe and effective as the original biological medicines.
What biosimilars are currently being used in lymphoma?
Granulocyte colony stimulating factor (G-CSF)
There are currently five biosimilar medicines approved by the TGA in Australia for use in the lymphoma setting. The original biological medicine is filgrastim which was produced by the pharmaceutical company Amgen and patented under the trade name Neupogen™. Filgrastim is a manmade form of granulocyte colony stimulating factor (G-CSF) which is a substance produced by the body to stimulate the growth of neutrophils.
As neutrophils are a type of white blood cell which are important for the body’s fight against infection, filgrastim can be given to patients having treatment for their lymphoma to help support their neutrophil count which is lowered with the treatment they are receiving or in higher doses to mobilise a patients stem cells from the bone marrow to the peripheral blood for collection on an apheresis machine. Once this biological medicine came off of patent other companies were able to produce a biosimilar medicine and currently there are three biosimilars for filgrastim in Australia with the trade names Nivestim™ produced by Pfizer, Tevagrastim™ produced by Teva and Zarzio™ produced by Sandoz.
Rituximab (MabThera) is one of the first complex monoclonal antibodies to have a biosimilar approved in Australia. There are currently two biosimilars for rituximab in Australia with the trade names Riximyo produced by Sandoz and Truxima produced by Celltrion.
How are they trialled and approved?
A biosimilar goes through extensive tests in a laboratory and in small clinical trials to compare it with the original medicine. It must match in quality, safety, and efficacy (how well it works).
Then a large clinical trial is carried out in a group of people with a disease that the original is used for. This is to confirm that the safety and efficacy match the original.
A biosimilar does not have to be tested in every disease that the original is approved for. These tests were done with the original medicine so there is already evidence that the medicine works in those diseases. If the biosimilar works well in 1 of them, there is no reason it would not behave in the same way in others.
Why are they developed?
The availability of biosimilars increases competition. Competition should drive down costs. Copying a successful medicine is much quicker than developing a new medicine. Fewer clinical trials are needed if it is already known which diseases a medicine works in. Biosimilars are usually much cheaper than the original medicine even though the quality of the medicines is the same.
Frequently asked questions
Biosimilar medications can be used whether you have been treated first with the Biologic.
Your hospital might switch brands of rituximab as biosimilars become available. Rituximab biosimilars are only given intravenously (through a drip into a vein). If you are already having intravenous rituximab, your hospital might want you to change brands if needed. They may change if they do not have your current brand in stock. Your doctor or pharmacist can answer any questions you may have about switching brands.
Only one brand of subcutaneous rituximab (given by injection under the skin) is currently available. If you are having subcutaneous rituximab (by injection under the skin), you are likely to continue with this for your course of treatment.
Talk to the doctor or nurse who is giving you the treatment. They will be able to answer any questions you may have about switching brands.
Biosimilars differ from generic medicines as generic medicines are the same active ingredient as the original chemical medicine. An example of a generic medicine is the original chemical medicine paracetamol which was patented as Panadol™ and the generic medicines include Panamax™ and Herron™ as examples.